Like many aquatic animals, helas are filter feeders. However, instead of swimming through liquid, the helas fly through the moist atmosphere of Enaleh, their mouths open wide, capturing thousands of tiny, flying insects every hour. The only social behavior that helas exhibit is that of schooling. Helas are never found as individuals. Instead, they are always part of a large group (usually numbering approximately 100 individuals). While, these "schools" of helas provide a limited amount of social interaction, they are primarily a defensive mechanism.

The main predators of the helas are the slards, large, quadrupedal felines that live in the Enaleh grasslands. The slards prey on helas by leaping out of their hiding places in the grasses and up into the air (sometimes leaping as far as four meters vertically), and capturing a hela as it flies above. The hela schools lessen the effectiveness of this method of attack by providing the slards with an overwhelming number of targets. Therefore, only one or two helas will fall while the rest of the school goes on. As a corollary to this, individual helas that become separated from their school (usually only the weak or old) are easily targeted by the attacks of the slards.

With the exception of the aquatic environment that is necessary for their embryonic development, helas spend their entire lives in the air. Most of this time is spent over the grasslands, but once during every local year, the helas gather above the lakes and freshwater seas to perform their reproductive behaviors.

Fertilization begins when the female helas fly over the water, very near the surface, and expel large numbers of eggs, which form a thick, yellow mass that covers much of the surface of the lake. The females then fly up into the sky and begin performing a complex series of aerial maneuvers. These maneuvers trigger the mating behavior of the males, who begin diving repeatedly into the water, filling the water with gametes. The acid of the gametes combines with carbonic compounds located in the silt that rests at the bottom of the lake, initiating the release of large amounts of carbon dioxide. As a result, the lake which the helas are using for their breeding grounds temporarily becomes a boiling soup - this mechanical action facilitates the fertilization of eggs. In addition, the sudden increase in carbon dioxide ensures that the lake will be filled with plant life for the embryonic helas to use as food.

Helas are notable for certain strange behaviors which are precipitated by the operation of mechanical repulsorlift generators. Helas have the ability to sense repulsorlift fields over long distances and are inexplicably drawn to them. Once the helas have located the field, they will perform one of two behaviors. They will either adopt the device that is generating the field into their school, swimming through the air with it and matching its every movement, or they will attack the device with their small but extremely sharp teeth.

Helas are rarely found on planets other than Enaleh. Smaller specimens have been exported and used in aeroquaria, but the helas are relatively fragile creatures, and these captive specimens live short lives and rarely breed. Periodically, someone attempts to start large scale farming and breeding of the helas, and these farms are often successful (and profitable) for a short time, but they almost always fail after a few seasons.

Many scientists have attempted to locate and examine the organ which allows the helas to generate their repulsorlift field, but none have been successful. However, a number of smugglers have found that they can supplement their incomes by providing helas to any of a number of research institutions.